i recently thought about how to order or categorize the layouts, so that the drop-down menu doesn't simply get longer and longer the more layouts gmb has by default.
the only category i could think of that makes sense to me and that would be understandable by anyone - meaning also people that don't know what a "browser" or a "simplesearch" or anything like that is - is "used screen estate", meaning size.

maybe we could start by adding those categories (small, medium, large) as headers in the layouts-dropdown like in the simplesearch-suggestions and sort them accordingly?

ochosi, I like that suggestion very much.

I don't know about changing the names, but you can already put layouts in categories, I didn't document this because at the time I wasn't sure of how it should be done (for a time, categories in the layout name, separated with a slash, was supported, but I removed it).
Just add a "Category= ACategoryName" line in the layout, and it will appear in a submenu.
I plan to make use of it soon so that I can add many contrib layouts without making the layout list a mess.